To put it simply, essential oils are natural while fragrance oils are synthetic products.
Essential oils are pure, steam-distilled plant extracts obtained from aromatic plants only. They are used for emotional healing, as natural remedies and in natural beauty products.
Fragrance oils are synthetic compounds, made in a lab. They can be toxic and irritating to the skin and lungs. They have absolutely no therapeutic benefits and can do harm to your health. It is possible to make any aroma synthetically in a lab. In stores you might see banana oil, strawberry oil, musk oil or maybe even bubble gum oil!